The present invention relates to a monitoring control device for tower cranes, in particular for small cranes, with integration of a set of functions, and adapted for radio control.
In the field of radio controlled mechanisms with speed regulator, for tower cranes, there exist radio control systems composed of a transmitting unit, incorporated into the control facility used by the crane driver, and of a receiving unit situated in the electrical cabinet for controlling the crane, the receiving unit customarily being hooked up to the connector of a conventional cable-based remote control. Systems for managing safety features by redundancy of identical circuits or by redundancy with diversity, based on circuits which may be electromechanical or electronic, are also known in this field.
By contrast, at present there exist no devices which group together and combine, within one and the same unit, the radio control function and the control monitoring function, carried out hitherto by relaying, as well as certain particular functions such as: controls for erecting the crane, in particular for automated erection; emergency controls for the erection and working of the crane; monitoring of the action of the safety devices; crane anti-overturning safety feature; wind speed sensors.
In particular, the aforesaid functions do not customarily exist for small cranes, which constitute the main field of application of the present invention, the cost of these functions, when they are separated from one another, being regarded as too high in consideration to the overall price of the crane.
1. Field of the Invention
The present invention is therefore aimed at bringing the cost of these functions, through their integration, to an acceptable level for small cranes, in such a way as to achieve a significant technological advance, endowing them with a technical nature, a diversity of functions and a degree of safety which are comparable with those of larger cranes for an affordable price.
2. Description of the Related Art
More particularly, the aim of the invention is to improve the safety of operation of such cranes, in particular through a simplification of the control circuits which is related to the integrating of the functions into a single electronic unit, with in particular:
a) processing of the safety aspects of the crane, such as:
active use of signals from an anemometer and from an inclinometer,
monitoring of brake dropout under the action of safety devices,
remote control of slewing,
use of potentiometric sensors or strain gauge sensors, allowing their permanent monitoring;
b) processing of the reliability of the control system by reducing the number of components and of connections and by customizing the control, for example:
elimination of programmable controllers,
elimination of relaying or of interfaces between systems,
elimination of certain cables, for example, the linking cable between crane and remote control,
reduction in the number of unpluggable connections,
reduction in the number of sensors,
adaptation of the crane to its operating conditions, in particular to its electrical, climatic and mechanical environment;
c) improvement of the maintainability of the crane by:
aids to driving, to maintenance, to erection and to operation,
adaptation to changes in the environment or to advances in technology,
remote interrogation of operating events.
Accordingly, the subject of the invention is essentially a control monitoring device which comprises, in respect of all the movements of the crane, such as hoisting, rotation, distribution and translation, a monitoring/control electronic unit receiving at its inputs and processing the control signal originating from the radio control box, as well as signals originating from sensors and from switches, and delivering start and stop commands at its outputs, while monitoring the action of the speed regulators or other control members assigned to the movements, as well as the action of the crane""s safety devices.
The monitoring/control electronic unit receives and processes in particular signals originating from position sensors and load sensors, a signal originating from a sensor for copying the state of the brake associated with each movement of the crane, a signal originating from a sensor of horizontality of a part of the crane, of the inclinometer kind, and a signal originating from an anemometer. The monitoring/control electronic unit can furthermore receive and process signals originating from a normal/emergency start switch.
As regards the output signals, the monitoring/control electronic unit delivers in particular a monitored start or stop command to the speed regulators, an instantaneous stop command sent to the same speed regulators, and a signal directed to a general cutout actuator.
In an advantageous embodiment, the monitoring/control electronic unit furthermore receives and processes signals originating from a normal/erection start switch, as well as signals related to the configuration of the crane during erection, and it comprises a sequencer receiving these signals and delivering signals for controlling actuators, such as rams, for the folding/unfolding of the crane in a continuous sequence.
The monitoring/control electronic unit can also deliver, by radio, information corresponding to the input signals processed, which information is transmitted to means for aiding driving, in particular in the form of an indicator placed on the radio control box.
The same monitoring/control electronic unit can furthermore deliver a signal for slewing the crane, on the basis of a slewing control signal emitted by the radio control box.